1. Field
The embodiments described below relate generally to the delivery of therapeutic radiation to a patient. More specifically, some embodiments are directed to the delivery of intensity-modulated radiation therapy.
2. Description
According to conventional radiation therapy, a beam of radiation is directed toward a tumor located within a patient. The radiation beam delivers a predetermined dose of therapeutic radiation to the tumor according to an established treatment plan. The delivered radiation kills cells of the tumor by causing ionizations within the cells.
Treatment plans are therefore designed to maximize radiation delivered to a target while minimizing radiation delivered to healthy tissue surrounding the target. Intensity-modulated radiation therapy (IMRT) can often deliver radiation doses that conform tightly to a target volume. In particular, conventional IMRT systems can provide fine control over a delivered dose distribution by manipulating the number, intensity, and point of entry of radiation beams which comprise an IMRT fraction.
In some scenarios, sensitive healthy tissues are located proximate to a target in a manner that prevents conventional IMRT systems from delivering an otherwise desired dose to the target without subjecting the healthy tissues to an undesirable dose. What is needed is a system to efficiently determine and/or deliver IMRT to a target volume with a more flexible dose distribution than conventionally available.